ALL the focus has been on Marcus Camby and the Knicks’ lack of rebounding since Game 1, but an old problem continued to haunt the Knicks in their series with Toronto.

They were losing the point guard battle.

What makes this even worse than past years, is the fact that ex-Knick Chris Childs rubbed it in their face by scoring 25 points in Toronto’s Game 4 victory that evened the series at 2-2. Childs’ stunning performance made last night’s win or go home game necessary.

Childs also has a way of getting under opponents’ skin, the way he’s constantly jabbering away.

It should. The Knicks sent Childs away thinking they were getting the better of the deal by acquiring old friend Mark Jackson. Although they brought the ex-Knick back, Jackson had not lived up to expectations. If he could lead the Knicks to victory last night it would make the deal look a lot better.

Jackson’s defensive liabilities have been noticeable and he had not been getting any help from Charlie Ward, who was the starter over Childs, but is now a backup. Ward has lost focus on his game since becoming embroiled in controversy over his anti-Jewish statements. Ward was a complete no-show in the 100-93 loss to Toronto Wednesday at Air Canada Centre.

The Raptors’ defensive game plan was simple. They were going to pressure scorers Allan Houston, Sprewell and Glen Rice, throwing double-teams at them and then dare Ward to beat them. They simply left Ward wide-open as if he wasn’t there. And he wasn’t. Ward was 1-for-4 in the game and missed three three-point shots. He was limited to 14 minutes of play and committed three turnovers in that short span. Other than Rice, who scored 19 points, the Knicks’ bench was useless. Othella Harrington did not score in 11 minutes and had only one rebound. Jackson hit three of his five shots, including one of two from three-point land and committed two turnovers in 35 minutes.

The Knicks were forced into 18 turnovers in that loss and that was something that had to change last night at the Garden. In the Knicks’ 97-89 victory in Game 3, the Knicks made only nine turnovers.

The turnovers are crucial because the Knicks were shooting the ball so well against Toronto’s lackadaisical defense. The Knicks shot 53 percent in Game 3 and 50 percent in Game 4.

The Raptors have won two of three games since inserting Childs into the starting lineup. During that time Childs has buried seven of 11 three-point attempts, an amazing 64 percent.

The Knicks needed to take the three away from Childs last night and they needed to do a better job defensively against the Raptors.

“They were up into us, pressuring us all game and we just let them bring the ball up the court and do anything they wanted,” Sprewell said of Game 4.

The Knicks know that Vince Carter can be unstoppable as he was in Game 4 when he electrified the Toronto crowd by scoring a career playoff-high 32 points. Childs also hurt the Knicks in that department, because Carter said Childs helped get him going. “Chris was always in my ear, talking to me, helping me out,” Carter said.

Said Childs of the emerging star, “He’s a young guy who’s still learning. The way you silence your critics you don’t have to speak a lot. You just go out there and play the game. He took it to heart. He didn’t wait. He stepped up. It’s our responsibility as veterans to let the young guys know this is how the game is going to be played.

“He listens,” Childs added of Carter. “A lot of young superstars in this league think they know everything. But he’s not like that.”

Childs had the chance to silence his biggest critics last night at the Garden. It will be a difficult challenge for Childs to duplicate his Game 4 performance on a court that brings back so many memories. It’s one thing to shine in front of your home crowd, it’s another to do it at the Garden, where Childs is now the enemy.

To beat the Raptors, a lot of the Knicks’ success depended on something as basic as communication. “We need to be ready from the start,” Sprewell said. “We need to be into the game and point out things to one another so we can all get the job done.”